Periodontal sulcus probing is a standard clinical technique for ascertaining periodontal and gingival condition. In such a procedure, the periodontist applies light hand pressure to the handle of the instrument to insert a thin rod-like probe tip into the sulci between the teeth and gingiva. Scale markings on the tip give a visual indication of the extent of penetration and, in particular, reveal the depth of periodontal pockets (diseased sulci) that may exist. The technique is described fully in publications such as Listgarten et al, Periodontal Probing and the Relationship of the Probe Tip to Periodontal Tissues, J. Periodontal. 511-413 (September 1976; Armitage et al, Microscopic Evaluation of Clinical Measurements of Connective Tissue Attachment Levels, J. Clin. Periodontology, 4:173-190 (1977); Hassell et al, Periodontal Probing: Interinvestigator Discrepancies and Correlations between Probing Force and Recorded Depth, Helv. Odont. Acta 17:38-42 (April 1973); Gabathuler et al, A Pressure-Sensitive Periodontal Probe, Helv. Odont. Acta 15:114-117 (October 1971); Glickman, Clinical Periodontology, 549-551 (4th Ed., W.B. Saunders & Co., 1972).
Pressure-sensitive periodontal probes have been used experimentally in an effort to ascertain the forces commonly applied by clinicians during such probing, and to investigate discrepancies and correlations between probing force and recorded depth. Thus, in Hassell et al, Supra, forces and depths were measured by using a probe equipped with a piezoelectric sensor and a charge amplifier, and in Armitage et al, Supra, releasable plastic probe tips were deposited and cemented in the sulci or pockets of dogs, using a probe for applying consistent insertion forces, after which the dogs were sacrificed and the placement of the tips were histologically studied. Such investigations indicate that there are significant differences in probing force and detected depth for different clinicians. Even the same clinician may apply different probing force at different times or circumstances. Consistent depth readings require a readily ascertainable uniform force, but heretofore there has been no simple and reliable clinical device for assisting periodontists in establishing and controlling the forces applied by the tips of the instruments during periodontal probing procedures.
A main object of this invention therefore lies in providing a simple and easily used periodontal probe which can consistently measure gingival pocket depths utilizing the same applied force at each and every site. Another object is to provide a probe which can be readily manipulated to apply a constant predetermined probing force but which, at the same time, is durable, easily cleaned and sterilized, and sufficiently free of mechanical and/or electrical complexity and bulk to facilitate use by a periodontist following the same procedures used with conventional probes. A still further object is to provide a periodontal probe which is constructed so that the force applied by the tip of the probe may be temporarily selectively increased by the periodontist during those moments when so depth reading is to be taken, for example, when the tip of the probe is being directed towards a sulcus and detached soft tissue must be displaced before measurements of pocket depth can begin.
In brief, the probe includes a handle provided at its head end with a transversely-extending sleeve, the sleeve slidably receiving a probe shaft. A thin leaf spring is secured at one end to the handle and engages bearing means provided by the probe shaft to urge that shaft in one direction. During a probing procedure, the leaf spring permits displacement of the shaft when the tip of that shaft is inserted into a gingival pocket. A depth reading is made from scale or fiducial markings on the probe tip while the tip is being pushed just hard enough to displace the shaft a predetermined extent against the force exerted by the leaf spring. Such extent of displacement is visually determined and is representative of a predetermined probing force to be applied by the instrument at the time a depth reading is to be taken. Because the leaf spring extends generally along the handle of the instrument near the head end thereof, a user may, if desired, increase the force to be applied by the probe tip simply by placing his index finger upon that spring as the probe tip is advanced.
Other advantages, objects, and features of the invention will become apparent from the specification and drawings.